1. Field of the Invention
The invention relates to an apparatus for storing in a first recording step, a first digital information signal in a first storage region of a storage medium.
The invention also relates to a method for carrying out a recording and a subsequent edit step, and to a record carrier obtained with the apparatus or the method. More specifically, the invention relates to an apparatus of the helical scan type, for recording in a recording step, a digital video signal and a corresponding digital audio signal in first track portions on a record carrier.
2. Description of the Related Art
An apparatus for recording and/or reproducing a digital video signal is known from EP-A 492,704, corresponding to U.S. Pat. No. 5,245,483, document D1 in the list of related documents that can be found at the end of this description. The digital video signal is data compressed and subsequently channel encoded so as to obtain a signal that is suitable for recording in the first track portions in the tracks. The data compression technique carried out on the digital video signal may result in the digital video signal to be encoded into an MPEG encoded digital information signal.
The MPEG encoded information signal comprises transport packets that may occur irregularly in the serial datastream of the MPEG transport stream received. The ISO/IEC 13.818 international standard, part 1 `Systems`, dated Nov. 13, 1994, document D2 in the list of related documents, comprises a description of a transport system for transmitting an MPEG information signal, which may include a data compressed digital video signal and a corresponding data compressed digital audio signal, for broadcasting purposes or for transmission via a cable network. The MPEG information signal is in the form of transport packets comprises 188 bytes of information each.
Packets in the MPEG serial data stream comprise, apart from `system information`, one kind of information, that is: either a portion of a video signal, or a portion of an audio signal, or a portion of a data signal. A plurality of video signals and/or a plurality of audio signals and/or a plurality of data signals may be transmitted via the transport packets in the MPEG serial data stream. A packet also comprises information of only one of the video signals, or one of the audio signals or one of the data signals transmitted via the MPEG serial data stream. Further packets are present in the serial datastream which comprise information about which of packets belong to one and the same video or audio signal, and information indicating which of the video and audio signals belong together and form a so-called `program`.
A transmission of such MPEG information signal, in the form of a recording on and a reproduction from a record carrier, requires special measures to be taken in order to realize such kind of transmission.
Earlier filed applications U.S. Ser. No. 08/225,193, having a filing date of Aug. 4, 1994, now U.S. Pat. No. 5,579,183 (PHN 14.818), document (D3) in the list of related documents, and U.S. Ser. No. 08/253,535, having a filing date of Mar. 6, 1994, now U.S. Pat. No. 5,596,581 (PHA 21.886), document (D4) in the list of related documents, describe various of such measures to realize a recording and reproduction of an MPEG information signal.
It can generally be said that the recording of a complete MPEG information signal is not well possible, because of the too high data rate of the MPEG information signal.
One of the video signals and its corresponding audio signal(s) included in the MPEG serial datastream are now selected for recording. As a consequence, generally, transport packets will be selected on an irregular basis as a function of time. In order to preserve the timing relation between the subsequent packets selected, after having recorded and reproduced the packets, the earlier filed documents describe the measure to insert timing information (or a `time stamp`) in each of the packets recorded. Upon reproduction, the timing relation between the subsequent packets can be regained using the time stamps. The packets thus obtained are recorded in the first track portions after having been subjected to a channel encoding step.